Main answer: The ball's speed at the instant in terms of its terminal speed can be determined using the given information.
Explanation: The acceleration with a magnitude of ହ ଷ ???? is not relevant to finding the ball's speed at this instant in terms of its terminal speed. However, we know that when the ball reaches its terminal speed, the net force on the ball is zero. At terminal speed, the force due to air resistance is equal in magnitude and opposite in direction to the force due to gravity.
Therefore, the ball's speed at this instant can be expressed as a fraction or multiple of its terminal speed. However, without knowing the specific values or relationship between the ball's speed and terminal speed, it is not possible to provide a more precise answer.
To find the ball's speed at this instant in terms of its terminal speed, you would need additional information or a specific equation relating the two.